This invention relates to a process for producing hydroquinone and more particularly, it relates to a process for producing hydroquinone by biochemical oxidation of benzene and/or phenol.
Hydroquinone is an industrially important compound which is widely used as photographic developers, antioxidants and synthetic intermediates.
At present, hydroquinone is mainly prepared by chemical synthesizing methods, which have defects such as complexity of process, by-production of catechol in large amounts which causes increase in load at the subsequent removal step and difficulty in balancing of supply and demand of both the compounds.
Thus, a process for producing hydroquinone which is free of these defects has been demanded.
Generally, biochemical oxidation has a high selectivity and yields substantially no by-products and has advantages on these points.
This is also applicable to production of hydroquinone and there have been processes for production of hydroquinone with microorganisms, for example, in Japanese Patent Laid-Open Applications (Kokai) No. 157895/79, No. 47496/83 and No. 65187/82. However, in these processes only two microorganisms, Methylosinus trichosporium and Methylococcus capsulatus which are methane-assimilating bacteria are used.
After the inventors' intensive researches on biochemical oxidation, it has been found that some of microorganisms belonging to either of Rhodococcus or Mycobacterium have ability to oxidize benzene or phenol to product hydroquinone. The inventors have established a process for production of hydroquinone with use of benzene or phenol as a starting material and of said microorganisms. This process is simple and produced hydroquinone in high yield without by-products, because the reaction proceeds position-specifically.